The GB2 has and still remains as the ultimate benchmark ball.  It's literally the first out of my bag for tournaments.  I currently have over 200 games on it and it's still going strong.  Sooner or later, I will have to replace it.  Are there any other great benchmark balls with a similar reaction?  BTW, I haven't tried any of the other GB2's except for the Gold.  I didn't care for that one at all. 

As long as it's still available, I would just look to purchase another GB2. If your looking to try something new and aren't brand specific, would definitely recommend the IQ Tour.

I second this.

I have several of the GB2 currently
I also had the gold, did not like it
the GB2 phenom is really good as well IMO
the sideswipe solid is my new favorite lately
longer and a bit stronger than the GB2, but also super predictable